Ammonium carbonate, solution preparation

The mauve colored cobalt(II) carbonate [7542-09-8] of commerce is a basic material of indeterminate stoichiometry, (CoCO ) ( (0 )2) H20, that contains 45—47% cobalt. It is prepared by adding a hot solution of cobalt salts to a hot sodium carbonate or sodium bicarbonate solution. Precipitation from cold solutions gives a light blue unstable product. Dissolution of cobalt metal in ammonium carbonate solution followed by thermal decomposition of the solution gives a relatively dense carbonate. Basic cobalt carbonate is virtually insoluble in water, but dissolves in acids and ammonia solutions. It is used in the preparation of pigments and as a starting material in the preparation of cobalt compounds. 

An autoclave (7) is supplied with an aqueous solution that contains 600 g of ammonium nitrate and 40 g of ammonia per litre. Calcium cyanamide in the ratio of 500 g CaCN2 to every litre of solution is then added from container (2) after being weighed at (3). The autoclave is closed, carbon dioxide is introduced, while the contents are cooled with water so that the temperature does not exceed 100°C. When no more carbon dioxide is absorbed, the supply is stopped, and so is the inflow of cooling water. The reaction mixture is now steam heated to 160°C. Afterwards a communicating valve joining the autoclave (7) with a second autoclave (75) is opened. The other vessel (75) is filled with ammonium nitrate solution prepared for the next charge. In this way the major part of the ammonia passes from autoclave (7) over to autoclave (75). After the reaction is finished the mixture is raised from the auto-... 

Complex Iron Carbonates.—Complex ammonium iron carbonates have been prepared in solution by adding excess of ammonium carbonate to ferrous or ferric salts in aqueous solutions. Ferric ammonium carbonate solution is blood-red in colour, and stable when kept in a closed vessel, but deposits ferric hydroxide on evaporation. Ferrous ammonium carbonate yields a colourless solution, which, upon oxidation in a limited supply of air, yields doubly refracting green prisms of basic ferroso-ferric ammonium carbonate, NH4.C03.Fe.C03.Fe.C03.Fe0.2H20. This, when treated with alkali hydroxides, yields magnetic ferroso-ferric oxide (see p. 144).1... 

Very pure oxide may be obtained when the beryllium nitrate prepared as described above is reconverted to the carbonate. An acid solution of the nitrate is evaporated in a platinum dish to remove excess acid, the residue is dissolved in some water, and enough distilled ammonium carbonate solution is added to redissolve the initially precipitated beryllium carbonate andgive a clear solution. The solution is then evaporated in a platinum dish until all the beryllium carbonate has separated as a coarse precipitate. After thorough washing with pure water and then with freshly distilled alcohol, the product is dried and finally calcined to the oxide in a platinum vessel placed in an electric furnace at 900°C. 

Trypsin solution 1 mg/mL mg trypsin dissolved (Promega, Madison, WI, USA) in 20 mM ammonium carbonate (freshly prepared). 

I ad(ll) carbonate Awhlte solid, PbC03, insoluble in water rhombic r.d. 6.6. It occurs as the mineral cerussite, which is iso-morphous with aragonite and maybe prepared in the laboratory by the addition of cold ammonium carbonate solution to a cold solution of a lead(II) salt (acetate or nitrate). It decomposes at 315°C to lead(II) oxide and carbon dioxide. 

Ammonium metavanadate has been prepared by dissolving the oxide in either aqueous ammonia or ammonium carbonate solution, but the large quantities of water required with these reagents lower the ammonium-ion concentration to such an extent that crystallization is difficult. Vanadium(V) oxide reacts readily with a solution of sodium carbonate, and ammonium metavanadate may be precipitated from the resulting solution by the addition of an ammonium salt. 

Elution from the cellulose phosphate column is with 10 per cent ammonium carbonate solution. With as little as 2-5 bed volumes of solution, 99 per cent recovery of thorium can be achieved. Uranium absorbed by the cellulose phosphate is also completely eluted. Three washes are interposed between absorption and elution, with 2N sulphuric acid, water and ammonia respectively. The sulphuric acid prevents hydrolysis and precipitation during the water wash, and the ammonia prevents evolution of carbon dioxide on elution with ammonium carbonate. Washes with water and then 2N sulphuric acid are similarly given after elution to prepare the column for the next absorption cycle. The thorium is recovered from the ammonium carbonate solution by boiling, when a precipitate of hydrated thorium oxide is formed, 99 per cent coming out of solution within 5 min. 

Finally, regarding the method of preparation, method B, in which the alkoxides are added to the ammonium carbonate solution, leads to surface areas, cumulative pore volumes and pore sizes higher than in the method A, due to an effect of increased local (NH4)2C03 concentration during the hydroxides precipitation step. 

Sample F prepared by precipitation of magnesium carbonate, which was produced by adding an ammonium carbonate solution to a solution of magnesium nitrate under stirring. The obtained white precipitate was the heated under stirring, washed, dried and filtered at 383 K for 8h, and calcined at 1173 K for 8h. 

Mist formation may also occur in gas/liquid reactions reactants may evaporate, react in the gas phase and form a liquid mist that will not coalesce with the other liquid phase. The temperature of the mist may rise, and uncontrolled reactions may take place in the mist particles. Examples of these are found in the processes for the manufacture of nitric and sulfuric acids, and in the preparation of ammonium nitrite from ammonium carbonate solution and nitrous oxides. In the nitric acid production, the product in the mist may be recovered by an effective separation of the mist particles (with demisters, wet scrubbers or electrostatic filters). But in the ammonium nitrite process, the product formed in the mist phase may subsequently decompose into nitrogen and water, thus reducing the process yield. 

Amino acids may be prepared by the action of a large excess of concentrated ammonia solution upon a-chloro- or a-bromo-acids the presence of a considerable amount of ammonium carbonate often increases the yield of monoamino acid, for example ... 

Lead Carbonate. Lead carbonate [598-63-0] PbCO, mol wt 267.22, d = 6.6g/cm, forms colorless orthorhombic crystals it decomposes at about 315°C. It is nearly insoluble in cold water (0.00011 g/100 mL at 20°C), but is transformed in hot water to the basic carbonate, 2PbC03 Pb(OH)2. Lead carbonate is soluble in acids and alkalies, but insoluble in alcohol and ammonia. It is prepared by passing CO2 iuto a cold dilute solution of lead acetate, or by shaking a suspension of a lead salt less soluble than the carbonate with ammonium carbonate at a low temperature to avoid formation of basic lead carbonate. 

Isolation of dry, normal ammonium acetate, prepared by neutralizing acetic acid with anhydrous ammonia or ammonium carbonate, is difficult because of ammonia loss during evaporation of water. Consequendy, commercial grades of ammonium acetate are often mixtures of the neutral and acid salts, or are suppHed as ammonium acetate solution [8013-61-4]. 

Ammonium cyanide may be prepared in solution by passing hydrogen cyanide into aqueous ammonia at low temperatures. It may also be prepared from barium cyanide and ammonium sulfate, or calcium cyanide with ammonium carbonate. It may be prepared in the dry state by gentiy heating a mixture of potassium cyanide or ferrocyanide and ammonium chloride, and condensing the vapor in a cooled receiver. Ammonium cyanide is soluble in water or alcohol. The vapor above soHd NH CN contains free NH and HCN, a very toxic mixture. 

Acetylene is passed for 1 hr through a mixture consisting of 0.5 g (72 mg-atoms) of lithium in 100 ml of ethylene-diamine. A solution prepared from 1 g (3.5 mmoles) of rac-3-methoxy-18-methylestra-l,3,5(10)-trien-I7-one and 30 ml of tetrahydrofuran is then added at room temperature with stirring over a period of 30 min. After an additional 2 hr during which time acetylene is passed through the solution the mixture is neutralized with 5 g of ammonium chloride, diluted with 50 ml water, and extracted with ether. The ether extracts are washed successively with 10% sulfuric acid, saturated sodium hydrogen carbonate and water. The extract is dried over sodium sulfate and concentrated to yield a solid crystalline material, which on recrystallization from methanol affords 0.95 g (87%) of rac-3-methoxy-18-methyl-17a-ethynyl-estra-l,3,5(10)-trien-17jB-ol as colorless needles mp 161°. 

As described in U.S. Patent 427,564, aminosalicylic acid may be prepared from m-amino-phenol by heating with ammonium carbonate in solution under pressure. 

A) Preparation of p-Hydroxy-p -Methoxybemhydrylidenecyclohexane To a Grignard solution prepared from 110 g of magnesium (4.5 mols) and 840 g of p-bromoanisole (4.5 mols) in one liter of anhydrous ether, there was added dropwise with vigorous agitation 307 g of p-hydroxyphenyl cyclohexyl ketone (1.5 mols) dissolved in one liter of anhydrous ether. Upon completion of the addition the reaction mixture was refluxed for 2.5 hours with agitation, and was then cooled. Thereupon 15 mols of ammonium chloride dissolved in 3 liters of water were added. The ethereal layer was separated, washed with water, dried over anhydrous sodium sulfate and distilled. Yield 370 g. BP 180° to 190°C at 0.1 mm. The substance was recrystallized from a mixture of carbon tetrachloride and petroleum ether. MP 145° to 146°C. 

Either the Mohr titration or the adsorption indicator method may be used for the determination of chlorides in neutral solution by titration with standard 0.1M silver nitrate. If the solution is acid, neutralisation may be effected with chloride-free calcium carbonate, sodium tetraborate, or sodium hydrogencarbonate. Mineral acid may also be removed by neutralising most ofthe acid with ammonia solution and then adding an excess of ammonium acetate. Titration of the neutral solution, prepared with calcium carbonate, by the adsorption indicator method is rendered easier by the addition of 5 mL of 2 per cent dextrin solution this offsets the coagulating effect of the calcium ion. If the solution is basic, it may be neutralised with chloride-free nitric acid, using phenolphthalein as indicator. 

Thorium oxide on activated carbon was prepared by absorption of thorium nitrate from its solution in anhydrous acetone on the activated carbon Supersorbon. The excess solution was decanted, the catalyst was dried at 80 °C, and the adsorbed thorium oxide was decomposed by excess 5% ammonium hydroxide solution. After repeated washing and decanta-nation with distilled water and acetone, the catalyst was dried at 180°C. It was then stabilized by heating to 360°C for 5 hr in a stream of nitrogen. The content of thorium oxide was 2.9% (wt.). The BET surface area was 870 m2/g. Prior to kinetic measurements, the catalyst was modified by passing over acetic acid vapors (100 g acid/1 g catalyst). 

Prepare a solution of the saccharide to be aminated at a concentration of up to 1 percent (w/v) in an aqueous solution of saturated ammonium carbonate. Even higher concentrations of saccharides may be used if the carbohydrate being modified is abundant and inexpensive. 

Heat 3-nitrophthalic anhydride with ammonium carbonate to get 3-nitrophthalimide (I). Dissolve 4.3 g (I) in 50 ml 90% methanol and add 1.9 g sodium borohydride over 30 minutes while stirring vigorously at room temperature. Stir 2 hours, acidify with 20% HCI, evaporate in vacuum and treat the dry residue with acetone. Evaporate in vacuum to get 3.9 g (88%) 3-OH-4-nitrophthal-imidine (II) (recrystallize from acetone). Dissolve 3.9 g (II) in 40 ml 20% HCI and stir for 10 hours on water bath at 80-90°. Distill off HCI and stir residue with acetone. Filter and evaporate in vacuum to get 3.4 g 3-OH-4-nitrophthalide (III) (recrystallize from CHC 3 and can purify on column). Prepare an ether solution of CH2N2 and add to 1.93 g (III) in a 100 ml flask until a reaction is no longer evident. Add acetic acid to decompose excess diazomethane and evaporate in vacuum to get about 2 g of 2-methoxycarbonyl-6-nitrostyrene oxide (IV) (can purify on column). Dissolve 560 mg (IV) in 50 ml absolute methanol, add 50 mg Pt02 and hydrogenate as described elsewhere here (other reducing methods should work). Filter,... 

Instead of aqueous solutions, hot glacial acetic acid and anhydrous ammonia may be used. Ammonium acetate also is prepared by reaction of acetic acid with ammonium carbonate ... 

Ammonium carbonate is obtained by passing carbon dioxide into aqueous ammonia solution in a column or tower. Ammonia, carbon dioxide and water vapor are distilled and the vapors condensed into a sobd crystaUine mass. It also may be prepared by subliming a mixture of ammonium sulfate and calcium carbonate. 

It may be prepared in solution by the reaction of calcium cyanide and ammonium carbonate ... 

Bi0)2C03 also may be prepared by adding ammonium carbonate to a solution of bismuth salt. The nature of the product in the preparative processes depends on the nature of the subnitrate or the bismuth salt used, the amount of water and the temperature. 

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